From the US Center for Disease Control: What to Expect after Getting a COVID-19 Vaccine. Common side effects include Fever, Chills, Tiredness, Headache [0].
This is not unusual for some types of vaccines, however my spouse is a medical professional and we know many PAs, nurses, and doctors that have already gotten the vaccine and it does seem that the rebound effects of the vaccine are more severe than other vaccines. That said, they also reported feeling better in 24 hours or less.
Other gave sources. Just adding it’s not a concern. It’s the body’s immune reaction. That’s how the vaccine works, and it’s pretty common with vaccines.
There's already a potential bad batch of over 1 million vaccines already distributed [1]. I really don't know why anyone would trust getting the v1 of a novel type of vaccine.